1. Field of the Invention
The present invention relates to a chemical mechanical polishing conditioner and a method for manufacturing thereof, and more particularly to a chemical mechanical polishing conditioner which may provide a deformation compensation for an abrasive layer.
2. Description of Related Art
Chemical mechanical polishing (CMP) is a common polishing process in various industries, which can be used to grind the surfaces of various articles, including ceramics, silicon, glass, quartz, or a metal chip. In addition, with the rapid development of integrated circuits, chemical mechanical polishing becomes one of the common techniques for wafer planarization due to its ability to achieve global planarization.
During the chemical mechanical polishing process of semiconductor, impurities or uneven structure on the surface of a wafer are removed by contacting the wafer (or the other semiconductor elements) with a polishing pad and using a polishing liquid if necessary, through the chemical reaction and mechanical force. When the polishing pad has been used for a certain period of time, the polishing performance and efficiency are reduced because the debris produced in the polishing process may accumulate on the surface of the polishing pad. Therefore, a conditioner can be used to condition the surface of the polishing pad, such that the surface of the polishing pad is re-roughened and maintained at an optimum condition for polishing. In the process for manufacturing a conditioner, it is necessary to dispose an abrasive layer by mixing abrasive particles and a binding layer on the substrate surface, and to fix the abrasive layer to the surface of the substrate by brazing or sintering methods. However, during curing the abrasive layer, the surface of the substrate may be deformed because of the difference in thermal expansion coefficient between the abrasive layer and the substrate, thus destroying flatness of the abrasive particles of the conditioner and thereby adversely affecting the polishing efficiency and service life of the conditioner.
In the known technology, it discloses an abrasive cloth dresser and a method for dressing an abrasive cloth with the same; wherein the dresser is aiming at an abrasive cloth dresser having a ring-shaped dressing face in the outer region of the base metal. The first abrasive grain units and the second abrasive grain units formed of abrasive grains with different grain sizes from each other are alternately arranged on the dressing face. The base metal includes adjusters for arbitrarily adjusting the height difference delta between reference planes and of the respective abrasive grain units, and the reference planes each include the ends of the abrasive grains with the largest grain size. However, the different degrees of high differences must be combined and adjusted by the adjusters, such as a base, a screw, a screw hole and so on through a mechanical method in the known technology.
Besides, in the other known technology, it discloses an assembled grinding machine, including: a big substrate, a plurality of elastic elements and a plurality of grinding units. Each of the plurality of the grinding units includes a plurality of grounding particles. Each of the grounding particles has a cutting end. The grinding units are coupled to the large substrate, respectively. The elastic elements are arranged between the grinding units and the big substrate, so that the elastic units can adjust the cutting end exceeding the big substrate. The grinding units are respectively coupled on the big substrate, so that the cutting ends of the abrasive particles on a big assembled grinding machine can have the same height. It is a low cost that the big grinding machine can be assembled by a plurality of small grinding units through different grinding particles optionally.
However, in the above-mentioned assembled chemical mechanical grinding machine, it is necessary to fix the grinding units to the bottom substrate by the adjusters. Besides, the tips of each grinding unit on the chemical mechanical polishing conditioner may result in the high differences due to the mechanical combination method. Therefore, the surface flatness of the chemical mechanical polishing conditioner is not easily controlled. On the other hand, if the grinding units are embedded and fixed to the holes of the bottom substrate, the bottom substrate of the chemical mechanical polishing conditioner is deformed after curing because of the differences in the thermal expansion coefficient between the grinding units and the bottom substrate. Furthermore, the surface of the chemical mechanical polishing conditioner is deformed therewith, and the flatness of the grinding particles on the surface of the conditioner is destroyed.
Therefore, what is needed is to develop a chemical mechanical polishing conditioner with surface flatness, which cannot only solve the deformation of the abrasive layer of the chemical mechanical polishing conditioner during curing, but also improve the surface flatness of the chemical mechanical polishing conditioner.